---
name: "pthread_attr_getschedparam"
section: "3p"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pthread_attr_getschedparam/3p"
---

# pthread\_attr\_getschedparam(3p)

get and set the schedparam attribute

## PROLOG

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

## NAME

pthread\_attr\_getschedparam, pthread\_attr\_setschedparam — get and set the schedparam attribute

## SYNOPSIS

```
#include <pthread.h>
```

int pthread\_attr\_getschedparam(const pthread\_attr\_t \*restrict *attr*,\
     struct sched\_param \*restrict *param*); int pthread\_attr\_setschedparam(pthread\_attr\_t \*restrict *attr*,\
     const struct sched\_param \*restrict *param*);

## DESCRIPTION

The *pthread\_attr\_getschedparam*() and *pthread\_attr\_setschedparam*() functions, respectively, shall get and set the scheduling parameter attributes in the *attr* argument. The contents of the *param* structure are defined in the *\<sched.h\>* header. For the SCHED\_FIFO and SCHED\_RR policies, the only required member of *param* is *sched\_priority*.

For the SCHED\_SPORADIC policy, the required members of the *param* structure are *sched\_priority*, *sched\_ss\_low\_priority*, *sched\_ss\_repl\_period*, *sched\_ss\_init\_budget*, and *sched\_ss\_max\_repl*. The specified *sched\_ss\_repl\_period* must be greater than or equal to the specified *sched\_ss\_init\_budget* for the function to succeed; if it is not, then the function shall fail. The value of *sched\_ss\_max\_repl* shall be within the inclusive range \[1,{SS\_REPL\_MAX}\] for the function to succeed; if not, the function shall fail. It is unspecified whether the *sched\_ss\_repl\_period* and *sched\_ss\_init\_budget* values are stored as provided by this function or are rounded to align with the resolution of the clock being used.

The behavior is undefined if the value specified by the *attr* argument to *pthread\_attr\_getschedparam*() or *pthread\_attr\_setschedparam*() does not refer to an initialized thread attributes object.

## RETURN VALUE

If successful, the *pthread\_attr\_getschedparam*() and *pthread\_attr\_setschedparam*() functions shall return zero; otherwise, an error number shall be returned to indicate the error.

## ERRORS

The *pthread\_attr\_setschedparam*() function shall fail if:

- **ENOTSUP**

  An attempt was made to set the attribute to an unsupported value.

The *pthread\_attr\_setschedparam*() function may fail if:

- **EINVAL**

  The value of *param* is not valid.

These functions shall not return an error code of **\[EINTR\]**.

*The following sections are informative.*

## EXAMPLES

None.

## APPLICATION USAGE

After these attributes have been set, a thread can be created with the specified attributes using *pthread\_create*(). Using these routines does not affect the current running thread.

## RATIONALE

If an implementation detects that the value specified by the *attr* argument to *pthread\_attr\_getschedparam*() or *pthread\_attr\_setschedparam*() does not refer to an initialized thread attributes object, it is recommended that the function should fail and report an **\[EINVAL\]** error.

## FUTURE DIRECTIONS

None.

## SEE ALSO

*pthread\_attr\_destroy()*, *pthread\_attr\_getscope()*, *pthread\_attr\_getinheritsched()*, *pthread\_attr\_getschedpolicy()*, *pthread\_create()*

The Base Definitions volume of POSIX.1‐2017, ***\<pthread.h\>***, ***\<sched.h\>***

## COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting\_bugs.html .